110300 McDonnell & Miller Replacement Switch Assembly – Model 5
🔥 Product Overview
The McDonnell & Miller 110300 Model 5 Replacement Switch Assembly is a genuine OEM automatic reset snap switch designed to restore proper pump and burner control in Series 93, 94, 193, and 194 low water cut-off/pump controller combinations. This multi-function, two-pole double-break switch allows simultaneous on/off operation of both pump and burner circuits, providing dependable boiler protection and water level management.
This switch is critical for maintaining safe boiler operation by ensuring proper response to changing water levels and system demand.
⚙️ Key Features
✅ Genuine McDonnell & Miller OEM replacement
✅ Automatic reset snap-action switch
✅ Two-pole, double-break design
✅ Simultaneous pump and burner control
✅ Supports alarm, valve actuation, and LWCO functions
✅ High 345 VA rating at both 120V and 240V
✅ Direct-fit replacement for Series 93, 94, 193 & 194 controls
✅ Restores safe boiler operation and reliability
📊 Specifications
| Specification | Details |
|---|
| Part Number |
110300 |
| Model |
5 |
| Brand |
McDonnell & Miller |
| Switch Type |
Automatic Reset Snap Switch |
| Configuration |
Two-Pole, Double-Break |
| Voltage Rating |
120 / 240 VAC |
| Volt-Amp Rating |
345 VA |
| Function |
Pump & Burner Control |
| Application |
Steam boiler LWCO / pump controller repair |
⚠️ Common Symptoms This Part Fixes
-
Boiler burner not turning on or off correctly
-
Feed pump failing to activate
-
Boiler shutting down unexpectedly
-
Alarm or auxiliary devices not engaging
-
Erratic water level control
-
LWCO failure codes or lockouts
-
Intermittent system cycling
🛒 Shopping Tips
• Confirm your control series: 93, 94, 193, or 194
• Match model number exactly — Model 5 is required
• Inspect wiring terminals during replacement
• Always disconnect power before servicing
• Consider replacing worn gaskets or terminal connectors at the same time
❓ Frequently Asked Questions (FAQ)
What does this switch control?
It simultaneously controls both the boiler feed pump and burner operation based on water level signals.
Is this an OEM McDonnell & Miller part?
Yes — this is a genuine OEM McDonnell & Miller replacement switch.
Does this switch automatically reset?
Yes — it features automatic reset snap-action operation.
Can I use this switch on other McDonnell & Miller models?
This switch is specifically designed for Series 93, 94, 193, and 194 combination controls.
Is professional installation recommended?
Yes — proper wiring and function testing should be performed by a qualified technician.
🔎 Compatible Controls
-
McDonnell & Miller 93 Series
-
McDonnell & Miller 94 Series
-
McDonnell & Miller 193 Series
-
McDonnell & Miller 194 Series
